The pour point of a hydrocarbon oil is measured according to the procedures described in ASTM test D97.
ASTM test D97 is comparatively time consuming and cumbersome, so it would be clearly desirable to have a convenient process to estimate the pour point of an oil.
Thus, it is not surprising that many previous attempts have been made to provide a convenient process to measure the pour point of oil.
The following U.S. patents relate to methods to estimate pour point, but none of the methods has achieved universal acceptance:
U.S. Pat. No. 3,580,047 (Simpson); U.S. Pat. No. 3,646,802 (Nolting); U.S. Pat. No. 4,508,460 (Croo); U.S. Pat. No. 3,498,104 (van Kerkvoort); U.S. Pat. Nos. 3,201,970; 3,202,602; 3,590,627 (Beaugh); U.S. Pat. No. 4,700,562 (Altman et al); U.S. Pat. No. 3,077,764 (Kapff); U.S. Pat. No. 3,248,928 (Conklin); U.S. Pat. No. 3,413,836 (Nadeau); U.S. Pat. No. 3,491,582 (Kleiss); U.S. Pat. No. 3,496,760 (Puzniak); U.S. Pat. No. 3,442,116 (Brown); U.S. Pat. No. 3,122,912 (O'Neill); and U.S. Pat. No. 3,161,039 (Kapff).
The inventions listed above have not received universal acceptance due to one or more perceived disadvantages, such as a lack of precision and/or accuracy in the test results; or due to the mechanical complexity of the machines required to complete the test. It is an object of the present invention to mitigate the disadvantages of the prior art attempts to estimate the pour point of oil.